The present invention relates generally to wire seals, and, more particularly, to wire seals which deter tampering with devices to which the wire seals are attached.
It is known that the theft of utilities, e.g., gas and electricity, from utility companies is a major source of financial loss each year for such companies. Even utility customers are perpetrators of this theft. One way of stealing services is by tampering with a utility meter which is installed at the customer's residence to measure and record the amount of gas or electricity consumed. In the case of electricity, an electrical watt-hour meter is typically installed at each customer's residence to measure and record the amount of electricity consumed by each customer in order that each customer may be accurately billed based on consumption level. However, dishonest customers tamper with the watt-hour meter in an effort to reduce the amount of consumption recorded thereon in order to correspondingly reduce their electric bill. Methods of tampering include bypassing the meter with conductive jumpers or reversing the polarity of the meter so that, as more electricity is used, the meter actually subtracts from the consumption level recorded. If the meter is returned to its normal operation just prior to the electric company reading it, the company will not be able to detect the customer's tampering with the meter.
Similar tampering is known to occur in other circumstances where other types of monitoring and/or recording equipment is installed at locations which prevent direct supervision by the equipment owner. Other devices which require prevention of tampering include shipping containers and the like. Shipping containers are normally left unattended by the owners of the contents for extended periods of time. Accordingly, sealing-type devices for providing visible evidence of tampering have been proposed in the prior art.
For instance, U.S. Pat. No. 1,863,041 to Dessauer discloses a device for sealing the ends of a string, cord or small wire in order to prevent the separation of the ends. The device is used to seal the ends of a cord which connects a tag to an article so that the tag can not be removed from the article. A two-part casing is disclosed which forms an inner area having a pair of resilient tongues formed therein. Further, a slide is disclosed as being contained in said casing. The slide has a notch and its own pair of resilient tongues formed thereon. In operation, the slide is removed from the casing so that the notch is accessible. The cord is wrapped around the slide in order to engage the notch. The slide is then forced inside the casing until the slide tongues engage the casing tongues and prevent the removal of the cord from the casing. Successful utilization of the Dessauer seal is dependent on correctly wrapping the cord around the slide before completely inserting the slide inside the casing. Disadvantageously, if a user of the seal does not properly engage the cord in the notch of the slide, the slide may not properly insert in the casing such that the respective tongues of the casing and the slide will not engage and, therefore, not prevent removal as intended.
A similar seal device is disclosed in U.S. Pat. No. 1,992,868 to Krause. The Krause reference also discloses a device which includes a case and a slide for sealing items such as car doors, heaters, tanks, hampers and the like. The slide has several holes passing therethrough as well as an inclined resilient latch. The case has a tubular form and has a keeper portion formed therein for engaging the inclined resilient latch of the slide. In operation, a link (i.e., similar to the cord used in the Dessauer device) is partially woven through certain of the holes formed in the slide. The slide is then partially inserted into the case where it temporarily engages the keeper in order to allow more of the link (cord) to be passed through the remaining holes on the slide. The slide is then completely inserted into the case and is held against removal by the keeper portion of the case. Again, proper operation of the seal disclosed in the Krause patent directly depends on how well the user follows the multiple steps associated with weaving the link among the holes in the slide.
U.S. Pat. No. 2,717,170 (Percival et al.) and U.S. Pat. No. 2,712,958 (Stelzer) disclose folding-type seals which are intended to be tamper resistant. The Percival et al. reference discloses a seal which includes three sections (a center section and first and second side sections) separated by weakened lines in the form of a scoring or groove. The cord to be sealed is laid over the center section and the first side section, having serrated flanges, is folded over and onto the center section such that the serrated flanges engage the cord and force the cord into the center section. The second side section is then folded over and onto the first side section and engages a shallow groove to keep the second side section flat against the first side section. If someone attempts to lift the top section, the weakened line will break and, thereby, provide evidence of the attempted tampering. Stelzer discloses a folding-type seal with only two sections; however, the general principle of operation is the same as that employed in the Percival et al. seal. One major disadvantage associated with the folding-type seal devices is that, if before being used, the sections are accidentally folded at the weakened score lines, the sections may break off at the time of use, thereby, rendering the device substantially useless.
Still further, a seal for meters and the like is disclosed in U.S. Pat. No. 3,980,332 to King. The King device includes a housing, a stiff spring wire shackle and a semi-resilient plastic keeper. The wire shackle is generally U-shaped with legs connected by a loop portion and with the free ends of the legs being inwardly and upwardly bent to form reversely bent hook portions. In operation, the wire shackle is passed through the hasp assembly of a meter and then inserted into a top opening of the housing until the hook portions bottom out on stops formed inside the housing. The keeper is then inserted into the opposite end of the housing so that notches formed thereon engage the hook portions of the wire shackle. Stops formed on the keeper engage the outside of the housing so that a bottom portion of the keeper remains outside the housing. It is intended that the only way for the seal to be broken is by breaking the bottom of the keeper along a perforation between the outside stops which allows the keeper and the wire shackle to be pushed out the top opening of the housing. The stiff construction of the portion which engages the meter hasp assembly, i.e, the wire shackle, is disadvantageous in that its lack of flexibility may make it difficult to install in tight compartments and more susceptible to accidental damage to the seal if the seal becomes caught on the clothing or other article of a passerby.
U.S. Pat. No. 5,114,196 to Storer discloses a similar locking device including a female member with apertures for threading a cable through whereby a male member is then inserted into a center aperture to forcibly retain the cable therein. However, the patent discloses that the cable must be thread through various apertures of the female member, at least four times, in order to properly ensure that the cable will be retained once the male member is fitted into the female member.
Similarly, U.S. Pat. No. 1,977,301 to Bradford discloses a seal which includes a cylinder with a cylindrical bore and circumferential groove formed therein. The Bradford seal discloses a plug with a pair of holes for allowing the ends of a band to be placed therethrough and a recess for receiving a splice that serves to connect the ends of the band after having been inserted through the holes of the plug. A spring ring is placed in a circumferential groove of the plug. Once the ends of the bands are placed through the plug and spliced, the plug is inserted into the bore of the cylinder whereby the spring ring placed in the groove of the plug engages the groove of the cylinder so that the plug can not be removed from the cylinder. Again, similar to the Storer device, extensive manipulation of the band or cord is required to secure it through one of the seal members. A single-use seal lock for mailbags is disclosed in U.S. Pat. No. 3,591,223 to Neto which includes a socket member and a plug which is insertable into the socket member. However, the seal has limited utility since the socket and plug secure a band therebetween, the band being formed as part of an existing mailbag.
U.S. Pat. No. 5,048,881 to Renfro discloses a lockable seal ring for specific use with an electric meter. However, the seal ring is of one-piece construction and completely surrounds the circumferential periphery of the meter and, thus, does not provide the general flexibility of a wire seal.
There is, therefore, a need in the prior art for a wire seal for use with meter devices, storage containers and the like which requires a minimal amount of simple steps to install and which may be easily installed in constrained environments. There is also a need for a wire seal which is less susceptible to accidental damage but which also provides readily visible evidence of intentional tampering therewith.